Running core barrels through whipstocks

At a recent DWOP, we were discussing the plan to cut 30 ft of  8"" core in a sidetracked section.

The initial bore is vertical 'FINDER well type' with minimal data acquisition planned.  In the 'success case', the well will be sidetracked to acquire a 30' core and perform a DST.

The whipstock (set in 9⅝") will result in 6°/100 ft dogleg severity (DLS). The coring assembly comprises 8"" corehead, 6¾" barrel.  The Coring Co advised that 3°/100 ft DLS is the maximum recommended.

We discussed options which include:

1. Section-milling a longer window (instead of the whip-stock) and kicking off a cement plug set across the window, but there's no guarantee that the DLS will be any less.
2. Setting whipstock as originally planned and drilling 8"" hole to core point and then running a smaller (6") coring assembly, which will easily pass through the window.

It would be good to hear from those of you have faced and overcome this challenge.

Thanks and kind regards

Dave

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